J. Appl. Cryst.の発刊に際して

Organic electronics are beginning to make significant inroads into the commercial world, and if the field continues to progress at its current, rapid pace, electronics based on organic thin-film materials will soon become a mainstay of our technological existence. Already products based on active thin-film organic devices are in the market place, most notably the displays of several mobile electronic appliances. Yet the future holds even greater promise for this technology, with an entirely new generation of ultralow-cost, lightweight and even flexible electronic devices in the offing, which will perform functions traditionally accomplished using much more expensive components based on conventional semiconductor materials such as silicon.

The path to ubiquitous and low-cost organic electronic appliances on plastic

A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

Since the discovery of highly conducting polyacetylene by Shirakawa, MacDiarmid, and Heeger in 1977, π-conjugated systems have attracted much attention as futuristic materials for the development and production of the next generation of electronics, that is, organic electronics. Conceptually, organic electronics are quite different from conventional inorganic solid state electronics because the structural versatility of organic semiconductors allows for the incorporation of functionality by molecular design. This versatility leads to a new era in the design of electronic devices. To date, the great number of π-conjugated semiconducting materials that have either been discovered or synthesized generate an exciting library of π-conjugated systems for use in organic electronics. 11 However, some key challenges for further advancement remain: the low mobility and stability of organic semiconductors, the lack of knowledge regarding structure property relationships for understanding the fundamental chemical aspects behind the structural design, and realization of desired properties. Organic field-effect transistors (OFETs) are a kind of device consisting of an organic semiconducting layer, a gate insulator layer, and three terminals (drain, source, and gate electrodes). OFETs are not only essential building blocks for the next generation of cheap and flexible organic circuits, but they also provide an important insight into the charge transport of πconjugated systems. Therefore, they act as strong tools for the exploration of the structure property relationships of πconjugated systems, such as parameters of field-effect mobility (μ, the drift velocity of carriers under unit electric field), current on/off ratio (the ratio of the maximum on-state current to the minimum off-state current), and threshold voltage (the minimum gate voltage that is required to turn on the transistor). 17 Since the discovery of OFETs in the 1980s, they have attracted much attention. Research onOFETs includes the discovery, design, and synthesis of π-conjugated systems for OFETs, device optimization, development of applications in radio frequency identification (RFID) tags, flexible displays, electronic papers, sensors, and so forth. It is beyond the scope of this review to cover all aspects of π-conjugated systems; hence, our focus will be on the performance analysis of π-conjugated systems in OFETs. This should make it possible to extract information regarding the fundamental merit of semiconducting π-conjugated materials and capture what is needed for newmaterials and what is the synthesis orientation of newπ-conjugated systems. In fact, for a new science with many practical applications, the field of organic electronics is progressing extremely rapidly. For example, using “organic field effect transistor” or “organic field effect transistors” as the query keywords to search the Web of Science citation database, it is possible to show the distribution of papers over recent years as shown in Figure 1A. It is very clear

Semiconducting π-conjugated systems in field-effect transistors: a material odyssey of organic electronics.

About Supramolecular Assemblies of π-Conjugated Systems

In X-ray computed tomography, the task of imaging only a local region of interest (ROI) inside a larger sample is very important. However, without a priori information, this ROI cannot be exactly reconstructed using only the image data limited to the ROI. We propose here an approach of region-of-interest tomography, which reconstructs a ROI within an object from projections of different fields of view acquired on a specific angular sampling scheme in the same tomographic experiment. We present a stable procedure that not only yields high-quality images of the ROI but keeps as well the quantitative contrast on the reconstructed images. In addition, we analyze the minimum number of projections required for ROI tomography from the point of view of the band region of the Radon transform, which confirms this number must be estimated based on the size of the entire object and not only on the size of the ROI.

/pdf/quantitative-region-of-interest-tomography-using-variable-3nypwhjabv.pdf

Quantitative region-of-interest tomography using variable field of view.

The ultrastructure of bovine femoral bone artificially heated at low temperatures (< 300 °C) is investigated by means of synchrotron quantitative scanning-SAXS imaging. Significant changes in the distribution of particle size are observed upon heating. On average, an exponential particle growth is measured with increasing temperature independently of the tissue histology. Additionally, the heating process induces a broader dispersion in the particle size which, in turn, seems to be dependent on the bone microstructure. Those parameters could therefore be used as markers in the characterization of archaeological bone presenting traces of heating.

/pdf/artificially-heated-bone-at-low-temperatures-a-quantitative-1vcv5xtq3h.pdf

Artificially Heated Bone at Low Temperatures: A Quantitative Scanning-small-angle X-Ray Scattering Imaging Study of the Mineral Particle Size

The first practical application of X-rays, more than 100 years ago, was for biomedical imaging. Although not central to the initial development of 3rd generation synchrotron light sources, imaging techniques have today established themselves as a core element of the research program at all major light sources, including the ESRF, where X-ray imaging has been identified as one of five main themes for its Upgrade Programme [1].

State of the Art and Perspectives of Biomedical Imaging at the ESRF

Toward Clinical X-ray Phase-Contrast CT

https://journals.iucr.org/m/issues/2019/02/00/ro5015/ro5015.pdf

Oliver Bunk

Papers

Quantitative region-of-interest tomography using variable field of view.

Artificially Heated Bone at Low Temperatures: A Quantitative Scanning-small-angle X-Ray Scattering Imaging Study of the Mineral Particle Size

State of the Art and Perspectives of Biomedical Imaging at the ESRF

Toward Clinical X-ray Phase-Contrast CT

X-ray scanning microscopies of microcalcifications in abdominal aortic and popliteal artery aneurysms